Baumer Capacitive Level Switches: How to Choose Between CleverLevel LBFS and LFFS
A level switch becomes difficult when the media is not simple water
Detecting a high or low level in a clean water tank is usually straightforward. The real selection problem starts when the same switch has to work with yoghurt, syrup, foam, powder, condensation, product coating or a hygienic process that gets cleaned regularly.
That is where buyers often make the wrong assumption about capacitive level switches.
They look at the connection size and output signal, then select a model. But with capacitance based level detection, the medium, dielectric constant, mounting, process connection and behaviour of material around the sensing tip matter just as much.
Baumer's CleverLevel range addresses this type of point level detection with the LBFS capacitive point level sensor and the LFFS CleverLevel switch. Both work with media having a dielectric constant above 1.5, but their configuration options and application possibilities are not identical.
What is a Baumer capacitive level switch?
A capacitive level switch detects whether material is present or absent at a fixed point in a tank, pipe or vessel.
It does not tell you that a tank is 42 percent full. That would require continuous level measurement. Instead, a point level switch answers a simpler but important question:
Has the product reached this point or not?
This signal can then be used for functions such as:
- High level alarm
- Low level alarm
- Tank overfill protection
- Pump dry run protection
- Empty pipe detection
- Product presence detection
- Media separation
- Automatic filling or emptying logic
Baumer uses its CleverLevel measuring principle for these applications.
How does CleverLevel actually work?
This is one of the useful details hidden behind the word "capacitive."
The measuring principle diagram on page 2 of the LFFS operating instructions shows an electrode inside the sensing tip forming a capacitor together with its surroundings. When the process medium changes, its dielectric constant changes the capacitance. The electronics combine this behaviour with a resonance circuit and evaluate the resulting frequency against programmed switching thresholds.
The LBFS datasheet describes this as CleverLevel Frequency Sweep technology.
In practical terms, the sensor is not simply waiting for electrical contact with the product. It evaluates how the electromagnetic behaviour around the sensing tip changes when product is present.
This makes the technology useful across very different media, provided the actual product and installation conditions are considered during selection.
Baumer CleverLevel LBFS
The Baumer LBFS is a compact capacitive point level sensor intended for both industrial and hygienic applications.
It makes sense when you need a small stainless steel point level device that can be mounted from the side, top or bottom of a tank or process connection and connected directly into an automation system.
The datasheet also specifies mounting from the top, bottom or side. Its wetted materials include PEEK and stainless steel, with AISI 316L as a primary option.
Technical points to note:
- Measuring principle: CleverLevel Frequency Sweep
- Media dielectric constant: above 1.5
- Repeatability: ±1 mm
- Hysteresis: ±1 mm
- Typical response time: 0.1 second
- Adjustable damping: 0 to 10 seconds
- Output configurations: PNP or NPN
- Switching logic: normally open or normally closed
- Supply: 12 to 30 V DC
- Protection: IP67 or IP69K with the appropriate cable
- Electrical options include M12 connector or cable versions
The LBFS product overview also lists marine, WHG and cULus approvals, with optional explosion protected configurations. Exact approvals depend on the selected ordering variant.
Where it is commonly used:
- Food and beverage tanks
- Dairy processing equipment
- Pharma and hygienic skids
- Water and utility tanks
- Process piping
- OEM filling equipment
- Pump protection
- High and low level alarms
For that reason, the complete ordering code matters.
Baumer CleverLevel LFFS
The Baumer LFFS is useful when the application requires more adjustment around difficult media or process behaviour.
The operating instructions specifically describe applications including tank level detection, media separation, empty pipe detection and pump dry run protection. The sensor can work with liquids such as water and beer, viscous or sticky products such as honey and yoghurt, and dry products such as sugar and flour.
The LFFS gives the engineer more control over that problem. Using Baumer's FlexProgrammer 9701 and Flex software, the output can be configured as PNP, NPN or digital, and the sensor can be adjusted for a particular medium. The manual also describes compensation settings for foam, bubbles, condensate and viscous media.
Technical points to note:
- Suitable for liquids and solids with dielectric constant above 1.5
- Outputs configurable as PNP, NPN or digital
- Supply: 12.5 to 36 V DC
- Output load: maximum 50 mA
- Adjustable output damping
- FlexProgrammer 9701 configuration support
- Teach in capability for empty and full conditions
- Hygienic installation options
- Resistant to CIP and SIP agents
- WHG certified for leakage and overfill protection
Where it is commonly used:
- Sticky food products
- Dairy tanks
- Beverage systems
- Powder and dry material detection
- Pump dry run protection
- Empty pipe detection
- High level protection
- Media separation applications
The LFFS instructions specifically warn that if sticky, foamy or powdery product remains around the tip during normal operation, that condition should also be present during teach in. Otherwise the calibration can be incorrect.
That is a practical point worth paying attention to during commissioning.
LBFS vs LFFS: Which Baumer level switch should you choose?
| Selection Point | LBFS | LFFS |
|---|---|---|
| Measurement | Point level | Point level |
| Media requirement | DC above 1.5 | DC above 1.5 |
| Main output options | PNP or NPN | PNP, NPN or digital |
| Configuration focus | Compact configurable product variants | More extensive media and output adjustment |
| Mounting | Top, bottom or side | Flexible mounting depending version |
| Difficult media | Suitable across diverse media | Specific compensation and teach in options for difficult media |
| Hygienic installations | Available with relevant process connections and accessories | Hygienic accessories and CIP/SIP suitability |
| Best fit | OEM, industrial and hygienic point level switching | Applications needing media adaptation and advanced commissioning |
The decision should not simply be "LBFS is smaller" or "LFFS has more settings."
The better question is:
How predictable is your process medium?
For straightforward point level switching with a suitable process connection and PNP or NPN output, the LBFS can be a very practical choice.
If your process involves product coating, foam, condensation, powders or changing media conditions where sensitivity needs to be tuned, the LFFS configuration capability becomes more important.
Key Selection Factors for Baumer Capacitive Level Switches
1. Check the dielectric constant
Both product documents specify applications with media having a dielectric constant above 1.5.
If your medium is unusual or close to the switching limit, confirm suitability before ordering.
2. Understand what the sensor will really see
Do not evaluate only the bulk product.
Ask whether the tip will also see:
- Foam
- Condensation
- Product coating
- Bubbles
- Sticky residue
- Powder build up
These conditions may affect commissioning and switching behaviour.
3. Confirm the process connection
The LBFS range includes multiple threaded, NPT, hygienic, cooling neck and sliding configurations.
For hygienic installations, Baumer notes that 3 A and EHEDG requirements depend on using the appropriate mounting accessories.
4. Confirm PLC input compatibility
If the switch is going into a PLC, relay module or control panel, confirm whether the input expects PNP or NPN logic.
Do not assume that every level switch can simply replace another model with the same connection thread.
5. Check actual process temperature and pressure
This is especially important with LBFS because the operating conditions table changes according to the exact connection and sensor construction.
Some special LBFS arrangements use cooling necks or sliding connections for higher process temperatures. Confirm the full ordering code instead of relying only on the general product overview.
6. Check whether hazardous area approval is required
LBFS is available with selected IECEx, CCC and ATEX configurations. The LFFS documentation also covers versions for hazardous gas and dust applications. Approval requirements must be matched to the exact area classification and device variant.
7. Do not ignore installation details
The LFFS manual makes several installation points that are easy to miss. The sensor should be installed in a closed metal pipe, tank or container, and the sensor tip needs the correct relationship to the surrounding metal for the measuring principle to work as intended. Hygienic installations also require the correct adapter and orientation.
Common Applications
Baumer capacitive level switches can fit applications such as tank high level detection, low level alarms, pump protection, empty pipe detection, dry media presence detection, process vessel switching, food product tanks and hygienic production equipment.
The LFFS documentation is particularly useful here because it gives real examples rather than simply saying "liquids and solids." It specifically lists water, beer, honey, yoghurt, toothpaste, ketchup, sugar and flour.
That range gives a good idea of why CleverLevel is interesting for applications where one plant may handle both thin liquids and products that leave residue on conventional probes.
Common Mistakes to Avoid
| Do This | Not This |
|---|---|
| Confirm the actual product and dielectric constant | Select only because the sensor is called capacitive |
| Consider foam and product coating | Test only in clean water |
| Match PNP or NPN output with the PLC input | Assume the existing wiring will work |
| Check complete LBFS ordering code | Order only by the LBFS model family |
| Select hygienic accessories together with the sensor | Assume any adapter maintains hygienic approval |
| Check process temperature and pressure by connection type | Use one temperature rating for every version |
| Perform teach in under real product conditions | Calibrate clean and ignore residue |
| Verify Ex requirement before purchase | Treat every variant as hazardous area approved |
Quick Selection Checklist
Before ordering a Baumer capacitive level switch, confirm:
- Product or media name
- Liquid, powder or sticky material
- Dielectric constant if known
- High level, low level, dry run or empty pipe application
- PNP, NPN or other required switching output
- Normally open or normally closed logic
- PLC, relay or control system connection
- Process connection
- Tank or pipe mounting position
- Process temperature
- Process pressure
- Hygienic requirement
- CIP or SIP requirement
- IP protection
- Hazardous area certification
- Need for teach in or media adjustment
Specifications to Confirm Before Purchase
Baumer offers many combinations, particularly within the LBFS ordering system. Final specification should therefore be checked against the exact selected variant.
Confirm the process connection, wetted material, temperature rating, pressure limit, supply voltage, switching output, cable or M12 connection, IP rating, hygienic approval, explosion protection, sensor length and mounting accessory before placing the order.
Why Buy Baumer Level Switches from Radical TechMart?
The difficult part of buying a level switch is usually not finding the model number. It is deciding whether that model will behave correctly once it sees the actual product inside the tank.
At Radical TechMart, the selection discussion can start from the application: media, tank, temperature, pressure, PLC input, hygiene requirement and required switching function.
This is particularly useful with products such as LBFS and LFFS because several sensor, connection and approval configurations are available.
Final Thoughts
A Baumer capacitive level switch should be selected around the process, not only around the thread size.
For a compact industrial or hygienic point level application, the LBFS gives a broad range of connection and configuration possibilities. For more demanding media behaviour where foam, coating, powder or changing process conditions need to be considered during commissioning, the LFFS offers useful teach in and FlexProgrammer adjustment capabilities.
In practical plant work, the best level switch is the one that still switches correctly after the process has been running for weeks, not just the one that works during the first water test.
FAQs
1. What is the Baumer LBFS?
The LBFS is a Baumer CleverLevel capacitive point level sensor for industrial and hygienic applications. It uses Frequency Sweep measurement and supports PNP or NPN switching configurations.
2. What is the Baumer LFFS used for?
The LFFS can be used for tank level detection, media separation, empty pipe detection and pump dry run protection. It supports liquids, sticky products and dry media with dielectric constant above 1.5.
3. Can Baumer CleverLevel detect powders?
Yes. The LFFS manual specifically gives sugar and flour as examples of dry media that can be detected. Suitability still depends on dielectric properties and installation conditions.
4. Can a Baumer capacitive level switch connect to a PLC?
Yes. LBFS is available with PNP or NPN output configurations. LFFS can be configured for PNP, NPN or digital output. The PLC input type and wiring must be confirmed before installation.
5. Is CleverLevel suitable for sticky products?
The LFFS documentation specifically mentions viscous and sticky products including honey, yoghurt, toothpaste and ketchup. It also provides media adjustment and teach in functions for difficult operating conditions.
6. Can the sensor be used in hygienic applications?
Yes, suitable LBFS and LFFS configurations support hygienic installations. For certifications such as 3 A or EHEDG, the appropriate mounting accessories and installation method must also be used.
7. Is Baumer LBFS suitable for high temperature applications?
Selected LBFS variants use cooling necks, extended hygienic connections or sliding connections for elevated process temperatures. The allowable limit depends on the exact ordering configuration, so the operating conditions table should be checked before selection.
8. What is the difference between LBFS and LFFS?
Both are CleverLevel point level devices for media with dielectric constant above 1.5. LBFS is a compact configurable sensor family with extensive connection choices, while LFFS documentation places greater emphasis on teach in, FlexProgrammer configuration and compensation for challenging media conditions.
